Q. When the light of our face goes to the glass, what is the path through which it goes called?
A. The line of the angle of incidence.
Q. When the light of our face is reflected back again from the mirror, what is this returning path called?
A. The line of the angle of reflection.
Q. Why does our reflection in a mirror seem to approach us as we walk towards it, and to retire from us as we retire?
A. Because the line of the angle of incidence is always equal to the line and angle of reflection.
Here CA, EA and DB, FB are the lines of the angle of incidence; and GA, KA and HB, LB are the lines of the angle of reflection. When the arrow is at CD, its shadow will appear at GH, because the line CA=GA and the angle CAB=angle GAB, &c.; and the same may be said about the point D.
Q. Why can a man see his whole person reflected in a little mirror not 6 inches in length?